I'd like to generate an output to visualize the RANS and the LES region for DDES.

My approach was to create an additional field containing the result of the fd function in spalartAllmarasDDES.C, which delimits the two regions, and to write it to a file.
Now, after some fruitless hacking attempts, it seems that I'm not enough a skilled programmer, so it would be great if anyone could give me a hint how to access the fd function and to create an output from it.